All views mode, Log class, bug fixes, optimizations, dead code removal

I tried to put the independent trivial changes at the start. The all-views mode is the meat of the pull request. Here's the docs for all-views mode, copied from README.md:

#### All-Views Mode

The `-A` option enables all-views mode.

All-views mode does a label-by-label import of every derived view from the
root view. The root view may be passed in with the `-v <view>` option or
will be automatically found by traversing up the view tree from the default
project view if no `-v <view>` option is given.

The `--skip-views <regex>` option may be given to prevent specific views
from being imported. All of the views that will be imported and skipped will
be logged at the beginning of the import run so that you may kill the import
and make changes if the list is not what you intend.

All-views is intended for one-time import of old project history. After the
initial all-views import, one of the other modes may be used with the `-R`
option to keep the git branches in sync with StarTeam.